When people use the word "light" in regards to money, it's most always in a derogatory sense.
You might have heard people say "sorry, I can't afford that honey I'm a little light" or "damn, I would go... but my wallet's a bit light". I understand that light can work in some situations like light beer (less calories) or light cigarettes (less tar) but I don't think people want "less money". imo
With this arguement the best could would be heavycoin or fatcoin, but you can probably see the issue. You can say just about any word will have a derogatory or negative sense. Its just a matter of context. But every biased opinion will see it their own way, yours included.
What really matters is how consumers perceive it generally.
The main problem with litecoin is that the name relays a message of "less" while the messages we ideally want to relay are ones like stored value, money, rarity, or wealth. To give a coin the best chance at conquering bitcoin, it should have at least one or more of these characteristics.